Method for forming on-site a coated optical article

ABSTRACT

The invention relates to a method for forming from a mold optical articles. These methods are particularly useful in preparing ophthalmic articles such as ophthalmic lenses, having several optical coatings thereon. The invention also relates to ophthalmic articles produced by these methods.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 60/294,426 filed May 29, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for forming from a moldoptical articles, in particular ophthalmic articles such as ophthalmiclenses, having several optical coatings thereon.

2. Previous Art

It is a common practice in the art to coat at least one face of anophthalmic lens with several coatings for imparting to the finished lensadditional or improved optical or mechanical properties. Thus, it isusual practice to coat at least one face of an ophthalmic lens substratetypically made of an organic glass material with successively, startingfrom the face of the substrate, an impact-resistant coating(impact-resistant primer), a scratch-resistant coating (hard coat), ananti-reflecting coating and, optionally, a hydrophobic top coat.

Typically, optical articles made of organic glass materials are formedin a mold comprising two separate parts having optical surfaces which,when the two-parts are assembled, define a molding cavity. A liquidcurable composition is then introduced in the molding cavity and curedto form the optical article. The optical article is thereafter recoveredupon disassembling of the mold parts.

Examples of typical two-part molds and molding methods are disclosed inU.S. Pat. Nos. 5,547,618 and 5,662,839.

It is known in the art to also apply a scratch-resistant coatingcomposition on the optical surfaces of the parts of a two-part mold, andif necessary precure it, assemble the mold parts, fill the moldingcavity with an optical liquid curable material, cure the opticalmaterial and disassemble the mold parts to recover the molded opticalarticle having a scratch-resistant coating deposited and adheredthereon.

Such a method is, for example, disclosed in document EP-102847.

U.S. Pat. No. 5,096,626 discloses a method for making an optical articlehaving a scratch-resistant coating and/or an anti-reflecting coatingthereon, which comprises:

-   forming an anti-reflecting coating and/or a scratch-resistant    coating onto the optical surfaces of a two-part mold;-   assembling the two-part mold;-   pouring an optical liquid curable composition in the molding cavity;-   curing the optical composition, and-   disassembling the two-part mold for recovering the molded optical    article having a scratch-resistant coating or a scratch-resistant    coating and an anti-reflecting coating thereon;    wherein, either at least one release agent is incorporated into the    scratch-resistant coating or a film of at least one release agent is    formed on the optical surfaces of the mold parts, prior to the    formation of the anti-reflecting coating and/or the    scratch-resistant coating.

The preferred release agents useful in the method of U.S. Pat. No.5,096,626 are fluorosilicones, fluoroalkylkoxysilanes and mixturesthereof.

U.S. Pat. No. 5,160,668 discloses a method for transferring ananti-reflecting coating onto a surface of an optical element whichcomprises:

forming on the optical surface of a part of a two-part mold a releaselayer of a water soluble inorganic salt;

forming on said release layer an anti-reflecting layer,

assembling the mold parts;

pouring a liquid optical curable composition in the molding cavity,

curing the optical composition,

disassembling the mold parts and dissolving the release layer in waterto recover the coated optical element.

U.S. Pat. No. 5,733,483 discloses a method for forming on-site tintedand coated optical elements from a mold which comprises:

forming successively on an optical surface of at least one part of atwo-part mold, a polymer release layer, an anti-reflecting coatinglayer, a coupling agent layer and a hard coat layer;

assembling the two-part mold;

pouring an optical liquid curable material in the molding cavity;

curing the optical material and the anti-reflecting, coupling agent andhard coat layers; and

disassembling the mold parts to recover the coated optical element.

The polymer release layer can be made of a water soluble polymer such aspolyvinylic acid (PAA), polyethylene-oxide (PEO),poly(N-vinylpyrolidone) (PNVP), polyvinylalcohol (PVA) or polyacrylamid(PAM); a non-water soluble and UV curable polymer such aspolybutadiene-diacrylate (PBD-SA), polyethyleneglycol-diacrylate(PEG-DA) or a highly crosslinked acrylate, and commercial mold releaseagents such as Dow-Corning 20 Release.

The coupling agent layer generally comprises a(meth)acryloxyalkyltrialkoxysilane. This coupling agent layer is used inorder to better extract the anti-reflecting coating from the mold.

What is needed is a method which will provide on-site formation ofoptical articles having thereon an impact-resistant coating, ascratch-resistant coating, an anti-reflecting coating and, optionally, ahydrophobic top coat by replication of a mold, thereby sufficientlyreducing required handling time and costs.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a method for forming from amold optical articles having an impact-resistant primer coating, ascratch-resistant coating, an anti-reflecting coating and, optionally, ahydrophobic top coat.

It is an additional object of this invention to provide a method forforming coated optical articles in which at least an anti-reflectingcoating, a scratch-resistant coating and an impact-resistant primercoating are transferred in a single step from at least one mold opticalsurface onto a surface of an optical substrate.

It is a further object of this invention to provide a method which doesnot necessitate the use of a coupling agent layer between theanti-reflecting layer and the scratch-resistant layer.

In accordance with the above objects and those that will be mentionedand will become apparent below, the method for forming a coated opticalarticle comprises:

providing a two-part mold having opposed optical surfaces definingtherebetween a molding cavity;

forming successively, on at least one of the optical surfaces of themold, an anti-reflecting coating, a scratch-resistant coating and animpact-resistant primer coating;

filling the molding cavity with an optical substrate liquid curablecomposition;

curing the liquid curable composition, and

disassembling the two-part mold for recovering a coated optical articlecomprising an optical substrate having deposited and adhered on at leastone of its faces, an impact-resistant primer coating, ascratch-resistant coating and an anti-reflecting coating.

In a preferred embodiment, the mold is made of a plastic material.

To further improve release of the coated optical article from the mold,a release agent can be incorporated in the plastic material of the mold,or the optical surfaces of the mold parts can be coated with a releaseagent layer.

In an additional preferred embodiment, to improve adhesion between thescratch-resistant coating and the impact-resistant primer coating orbetween the primer coating and the substrate, one or more couplingagents can be incorporated into the composition of the scratch-resistantcoating and/or of the primer coating.

The preferred coupling agent is a pre-condensed solution of at least oneepoxyalkoxysilane and at least one unsaturated alkoxysilane.

Preferably, the anti-reflective coating is a stack of alternated highand low refractive index inorganic material layers. To improve adhesionof such an anti-reflecting coating to the scratch-resistant coating athin layer of SiO₂ may be interposed between the anti-reflecting coatingand the scratch-resistant coating.

BRIEF DESCRIPTION OF THE DRAWING

For the further understanding of the objects and advantages of thepresent invention, reference should be made to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like parts are given like reference numerals and wherein:

FIG. 1A to FIG. 1C schematically illustrate the main steps of anembodiment of the method of the invention; and

FIG. 2A to FIG. 2C schematically illustrate the main steps of anotherembodiment of the method of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Although in the following description, only one face of the opticalarticle is being coated with the optical functional coatings accordingto the invention, it should be understood that both faces of the opticalarticles can be coated simultaneously using the method of the invention.

With respect to FIG. 1A, there is shown schematically a front part 10 ofa two-part mold, on the optical surface 10 a of which has beensuccessively formed an anti-reflecting coating 20, a scratch-resistantcoating 30 and an impact-resistant primer coating 31.

The two-part mold used in the method of the invention comprises a frontpart 10 having an optical surface 10 a and a rear part 11 (FIG. 1B)having an optical surface 11 a.

Typically the two-parts 10, 11 of the mold are assembled through agasket or an adhesive tape (not shown) so that the optical surfaces 10a, 11 a of the mold parts define therebetween a molding cavity.

Typically the mold parts 10, 11 are made of mineral glass or a plasticmaterial. In the method of the invention, the mold part are preferablymade of a plastic material, in particular a plastic material thatpromotes easy release of the molded optical article.

Among the plastic materials that can be used for the two-part mold therecan be cited: polycarbonates (PC), polyamides (PA), polyimides (PI),polysulfones (PS), copolymers of polyethyleneterephtalate andpolycarbonate (PET-CP), crystal polyethyleneterephtalate (crystal PET),glass fiber reinforced polyethyleneterephtalate, and polyolefins such aspolynorbornenes. The preferred plastic materials are polycarbonates andpolynorbornenes.

A very good plastic material that can be used for the two part mold is acopolymer having the following units

Such copolymer is available from Bayer under the commercial trade nameAPEC.

This copolymer has a high rigidity which can be an advantage for the useas a mold material.

Preferably, the thickness center for each mold part is at least 4 mm.

To enhance the release effect of the molds, in particular with regard tothe anti-reflecting coating, one or more release agents can beincorporated in the polymer material of the mold. Examples of suchrelease agents are trimethylchlorosilane, chloromethyltrimethylsilane,chloropropyltrimethylsilane, chloromethyldodecyl dimethylsilane,chlorine terminated polydimethyl siloxane, (3,3-dimethylbutyl)dimethylchlorosilane, hexamethyldisilazane, octamethyltetrasilazane,aminopropyldimethyl terminated polydimethylsiloxane, 3-trimethoxysilylpropyloctadecyldimethylammonium chloride, tetradecyldimethyl(3-trimethoxysilylpropyl) ammonium chloride, trimethylethoxysilane andoctadecyltrimethoxysilane.

If necessary the optical surfaces 10 a, 11 a of the parts of the plasticmold may be previously coated with a protective and/or release coatingwhich either protects the optical surfaces from defects such asscratches that may be created during handling, and/or enhance therelease effect. This protective and/or release coating may also even theoptical surface

Examples of such coatings are:

A UV-curable acrylic layer optionally containing at least one of theabove cited release agent or an amine containing polysiloxane layeroptionally containing at least one of the above release agent;

A fluorocarbon polymer layer, such as polytetrafluoroethylene (PTFE)polymers, for example Teflon® AF, Teflon® PTFE FEP and Teflon® PTFE PFA;

A buffer layer which may delaminate from the mold part optical surfaceand from which the anti-reflecting coating or the top coat can release,such as a vacuum-deposited magnesium fluoride (MgF₂) layer or a siloxanebase coating normally used to input scratch resistance to lenses. Bothof these layers release readily from the optical surface of the mold, inparticular of a polycarbonate mold. After demolding of the opticalarticle, these layers are eliminated.

The protective and/or release coatings can be deposited by dip coatingor spin coating, and depending upon their technical natures they may beUV and/or thermally cured or simply dried. Those protective and/orrelease coatings have typically a thickness of 2 nm to 10 microns.

The mold parts, usually made of plastic material, are UV transparent andallow UV and/or thermal curing of the different layers and in particularof the optical substrate composition. Preferably, the polymer materialof the mold parts are free of UV absorber.

As shown in FIG. 1A, there is first deposited on the optical surface 10a of the first part 10 of, for example, a polycarbonate mold, ananti-reflecting coating 20.

Anti-reflecting coatings and their methods of making are well known inthe art. The anti-reflecting can be any layer or stack of layers whichimproves the anti-reflective properties of the finished optical article.

The anti-reflecting coating may preferably consist of a mono- ormultilayer film of dielectric materials such as SiO, SiO₂ Si₃N₄, TiO₂,ZrO₂, Al₂O₃, MgF₂ or Ta₂O₅, or mixtures thereof.

The anti-reflecting coating can be applied in particular by vacuumdeposition according to one of the following techniques:

-   1)—by evaporation, optionally ion beam-assisted;-   2)—by spraying using an ion beam,-   3)—by cathode sputtering; or-   4)—by plasma-assisted vapor-phase chemical deposition.

In case where the film includes a single layer, its optical thicknessmust be equal to λ/4 where λ is wavelength of 450 to 650 nm.

Preferably, the anti-reflecting coating is a multilayer film comprisingthree or more dielectric material layers of alternatively high and lowrefractive indexes.

Of course, the dielectric layers of the multilayer anti-reflectingcoating are deposited on the optical surface of the mold part or thehydrophobic top coat in the reverse order they should be present on thefinished optical article.

In the embodiment shown in FIG. 1A, the anti-reflecting coating 20comprises a stack of four layers formed by vacuum deposition, forexample a first SiO₂ layer 21 having an optical thickness of about 100to 160 nm, a second ZrO₂ layer 22 having an optical thickness of about120 to 190 nm, a third SiO₂ layer 23 having an optical thickness ofabout 20 to 40 nm and a fourth ZrO₂ layer 24 having an optical thicknessof about 35 to 75 nm.

Preferably, after deposition of the four-layer anti-reflecting stack, athin layer of SiO₂ 25 of 1 to 50 nm thick (physical thickness) isdeposited. This layer 25 promotes the adhesion between theanti-reflecting stack and the scratch-resistant coating 30 to besubsequently deposited, and is not optically active.

The next layer to be deposited is the scratch-resistant coating 30. Anyknown optical scratch-resistant coating composition can be used to formthe scratch-resistant coating 30. Thus, the scratch-resistant coatingcomposition can be a UV and/or a thermal curable composition.

By definition, a scratch-resistant coating is a coating which improvesthe abrasion resistance of the finished optical article as compared to asame optical article but without the scratch-resistant coating.

Preferred scratch-resistant coatings are those made by curing aprecursor composition including epoxyalkoxysilanes or a hydrolyzatethereof, silica and a curing catalyst. Examples of such compositions aredisclosed in U.S. Pat. No. 4,211,823, WO 94/10230, U.S. Pat. No.5,015,523.

The most preferred scratch-resistant coating compositions are thosecomprising as the main constituents an epoxyalkoxysilane such as, forexample, γ-glycidoxypropyltrimethoxysilane (GLYMO) and adialkyldialkoxysilane such as, for example dimethyldiethoxysilane(DMDES), colloidal silica and a catalytic amount of a curing catalystsuch as aluminum acetylacetonate or a hydrolyzate thereof, the remainingof the composition being essentially comprised of solvents typicallyused for formulating these compositions.

In order to improve the adhesion of the scratch-resistant coating 30 tothe impact-resistant primer coating 31 to be subsequently deposited, aneffective amount of at least one coupling agent can be added to thescratch-resistant coating composition.

The preferred coupling agent is a pre-condensed solution of anepoxyalkoxysilane and an unsatured alkoxysilane, preferably comprising aterminal ethylenic double bond.

Examples of epoxyalkoxysilanes are γ-glycidoxypropyl-termethoxysilane,γ-glycidoxypropylpentamethyldisiloxane,γ-glycidoxy-propylmethyldiisopropenoxysilane,(γ-glycidoxypropyl)methyldiethoxy-silane,γ-glycidoxypropyldimethylethoxysilane,γ-glycidoxypropyl-diisopropylethoxysilane and(γ-glycidoxypropyl)bis(trimethylsiloxy)methylsilane.

The preferred epoxyalkoxysilane is γ-glycidoxypropyl-trimethoxysilane.

The unsatured alkoxysilane can be a vinylsilane, an allylsilane, anacrylic silane or a methacrylic silane.

Examples of vinylsilanes are vinyltris(2-methoxyethoxy)silane,vinyltrisisobutoxysilane, vinyltri-t-butoxysilane,vinyltriphenoxysilane, vinyltrimethoxysilane, vinyltriisopropoxysilane,vinyltriethoxysilane, vinyltriacetoxysilane, vinylmethyldiethoxysilane,vinylmethyldiacetoxy-silane, vinylbis(trimethylsiloxy)silane andvinyldimethoxyethoxysilane.

Examples of allylsilanes are allyltrimethoxysilane, alkyltriethoxysilaneand allyltris(trimethylsiloxy)silane.

Examples of acrylic silanes are3-acryloxypropyltris(trimethylsiloxy)silane,3-acryloxypropyltrimethoxysilane, acryloxypropylmethyl-dimethoxysilane,3-acryloxypropylmethylbis(trimethylsiloxy)silane,3-acryloxypropyldimethylmethoxysilane,n-(3-acryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane.

Examples of methacrylic silanes are 3-methacryloxypropyltris(vinyldimethoxylsiloxy)silane, 3-methacryloxypropyltris(trimethylsiloxy)silane, 3-methacryloxypropyltris(methoxyethoxy)silane,3-methacrylo-xypropyltrimethoxysilane, 3-methacryloxypropylpentamethyldisiloxane, 3-methacryloxypropylmethyldimethoxysilane,3-methacryloxypropylmethyl-diethoxysilane, 3-methacryloxypropyldimethylmethoxysilane, 3-methacryloxypropyldimethylethoxysilane,3-methacryloxypropenyltrime-thoxysilane and3-methacryloxypropylbis(trimethylsiloxy)methylsilane.

The preferred silane is acryloxypropyltrimethoxysilane.

Preferably, the amounts of epoxyalkoxysilane(s) and unsaturatedalkoxysilane(s) used for the coupling agent preparation are such thatthe weight ratio$R = \frac{{weight}\quad{of}\quad{epoxyalkoxysilane}}{{weight}\quad{of}\quad{unsaturated}\quad{alkoxysilane}}$verifies the condition 0.8≦R≦1.2.

The coupling agent preferably comprises at least 50% by weight of solidmaterial from the epoxyalkoxysilane(s) and unsaturated alkoxysilane(s)and more preferably at least 60% by weight.

The coupling agent preferably comprises less than 40% by weight ofliquid water and/or organic solvent, more preferably less than 35% byweight.

The expression “weight of solid material from epoxyalkoxy silanes andunsatured alkoxysilanes” means the theoritical dry extract from thosesilanes which is the calculated weight of unit Q_(k) Si O_((4-k)/2)where Q is the organic group that bears the epoxy or unsaturated groupand Q_(k) Si O_((4-k)/2) comes from Q_(k) Si R′O_((4-k)) where Si R′reacts to form Si OH on hydrolysis.

k is an integer from 1 to 3 and is preferably equal to 1.

R′ is preferably an alkoxy group such as OCH₃.

The water and organic solvents referred to above come from those whichhave been initially added in the coupling agent composition and thewater and alcohol resulting from the hydrolysis and condensation of thealkoxysilanes present in the coupling agent composition.

Preferred preparation methods for the coupling agent comprises:

1) mixing the alkoxysilanes

2) hydrolysing the alkoxysilanes, preferably by addition of an acid,such a hydrochloric acid

3) stirring the mixture

4) optionally adding an organic solvent

5) adding one or several catalyst(s) such as aluminum acetylocetonate

6) stirring (typical duration: overnight).

Typically the amount of coupling agent introduced in thescratch-resistant coating composition represents 0.1 to 15% by weight ofthe total composition weight, preferably 1 to 10% by weight.

The scratch-resistant coating composition can be applied on theanti-reflecting using any classical method such as spin, dip or flowcoating.

The scratch-resistant coating composition can be simply dried oroptionally precured before application of the subsequentimpact-resistant primer coating 31. Depending upon the nature of thescratch-resistant coating composition thermal curing, UV-curing or acombination of both can be used.

Thickness of the scratch-resistant coating 30, after curing, usuallyranges from 1 to 15 μm, preferably from 2 to 6 μm.

Before applying the impact resistant primer on the scratch resistantcoating, it is possible to subject the surface of the scratch resistantcoating to a corona treatment or a vacuum plasma treatment, in order toincrease adhesion.

The impact-resistant primer coating 31 can be any coating typically usedfor improving impact resistance of a finished optical article. Also,this coating generally enhances adhesion of the scratch-resistantcoating 30 on the substrate of the finished optical article.

By definition, an impact-resistant primer coating is a coating whichimproves the impact resistance of the finished optical article ascompared with the same optical article but without the impact-resistantprimer coating.

Typical impact-resistance primer coatings are (meth)acrylic basedcoatings and polyurethane based coatings.

(Meth)acrylic based impact-resistant coatings are, among others,disclosed in U.S. Pat. No. 5,015,523 whereas thermoplastic and crosslinked based polyurethane resin coatings are disclosed inter alia, inJapanese Patents 63-141001 and 63-87223, EP-0404111 and U.S. Pat. No.5,316,791.

In particular, the impact-resistant primer coating according to theinvention can be made from a latex composition such as apoly(meth)acrylic latex, a polyurethane latex or a polyester latex.

Among the preferred (meth)acrylic based impact-resistant primer coatingcompositions there can be cited polyethyleneglycol(meth)acrylate basedcompositions such as, for example, tetraethyleneglycoldiacrylate,polyethyleneglycol (200) diacrylate, polyethyleneglycol (400)diacrylate, polyethyleneglycol (600) di(meth)acrylate, as well asurethane (meth)acrylates and mixtures thereof.

Preferably the impact-resistant primer coating has a glass transitiontemperature (Tg) of less than 30° C.

Among the preferred impact-resistant primer coating compositions, theremay be cited the acrylic latex commercialized under the name Acryliclatex A-639 commercialized by Zeneca and polyurethane latexcommercialized under the names W-240 and W-234 by Baxenden.

In a preferred embodiment, the impact-resistant primer coating may alsoincludes an effective amount of a coupling agent in order to promoteadhesion of the primer coating to the optical substrate and/or to thescratch-resistant coating.

The same coupling agents, in the same amounts, as for thescratch-resistant coating compositions can be used with theimpact-resistant coating compositions.

The impact-resistant primer coating composition can be applied on thescratch-resistant coating 30 using any classical method such as spin,dip, or flow coating.

The impact-resistant primer coating composition can be simply dried oroptionally precured before molding of the optical substrate. Dependingupon the nature of the impact-resistant primer coating composition,thermal curing, UV-curing or a combination of both can be used.

Thickness of the impact-resistant primer coating 31, after curing,typically ranges from 0.05 to 20 μm, preferably 0.5 to 10 μm and moreparticularly from 0.6 to 6 μm.

The next step of the method is, as shown in FIG. 1B, assembling thefront part 10 coated with the anti-reflecting, scratch-resistant andimpact-resistant primer coatings 20, 30, 31 with the rear part 11 of thetwo-part mold as described, for example, in U.S. Pat. Nos. 5,547,618 and5,562,839.

The molding cavity is then filled with a liquid curable opticalcomposition which is cured to form the optical substrate 40.

The optical substrate can be made from any typical liquid, curablecomposition used in the optical field.

Examples of such optical substrates are substrates resulting from thepolymerization of:

-   -   diethylene glycol bis (allylcarbonate) based compositions,    -   (meth)acrylic monomer based compositions, such as compositions        comprising (meth)acrylic monomers derived from bisphenol-A;    -   thio(meth)acrylic monomer based compositions;    -   polythiourethane precursor monomer based compositions; and    -   epoxy and/or episulfide monomer based compositions.

Depending upon the nature of the curable optical material, the opticalmaterial can be thermally cured, UV-cured or cured with a combination ofboth, or cured at ambient temperature.

As shown in FIG. 1C, once the optical substrate 40 has been cured, andoptionally concurrently the scratch-resistant coating 30 and theimpact-resistant primer coating 31 if not previously cured, the moldpart 10, 11 are disassembled to recover the optical substrate 40 havingtransferred on one face, the impact-resistant primer coating 31, thescratch-resistant coating 30 and the anti-reflecting coating 20.

There is shown in FIGS. 2A to 2C another embodiment of the method of theinvention.

The essential difference between the method described in connection withFIGS. 1A to 1C and the method illustrated by FIGS. 2A to 2C is that anadditional hydrophobic top coat 50 is deposited onto the optical surface10 a of the front part 10 of the mold prior to the deposition of theanti-reflecting coating 20.

The hydrophobic top coat 50, which in the finished optical articleconstitutes the outermost coating on the optical substrate, is intendedfor improving dirty mark resistance of the finished optical article andin particular of the anti-reflecting coating.

As known in the art, a hydrophobic top coat is a layer wherein thestationary contact angle to deionized water is at least 60°, preferablyat least 75° and more preferably at least 90°.

The stationary contact angle is determined according to the liquid dropmethod in which a water drop having a diameter smaller than 2 mm isformed on the optical article and the contact angle is measured.

The hydrophobic top coats preferably used in this invention are thosewhich have a surface energy of less than 14 m Joules/m².

The invention has a particular interest when using hydrophobic top coatshaving a surface energy of less than 13 m Joules/m² and even better lessthan 12 m Joules/m².

The surface energy values referred just above are calculated accordingto Owens Wendt method described in the following document: “Estimationof the surface force energy of polymers” Owens D. K.—Wendt R. G. (1969)J. Appl. Polym. Sci., 1741-1747.

Such hydrophobic top coats are well known in the art and are usuallymade of fluorosilicones or fluorosilazanes i.e. silicones or silazanesbearing fluor-containing groups. Example of a preferred hydrophobic topcoat material is the product commercialized by Shin Etsu under the nameKP 801M.

The top coat 50 may be deposited onto the optical surface 10 a of moldpart 10 using any typical deposition process, but preferably usingthermal evaporation technique.

Although the deposition of the top coat is preferably made by transferfrom the mold, the top coat can be also applied by any classical means(for example dip coating) on an antireflective lens previously obtainedby the transfer method (without any top coat applied on the mold).

Thickness of the hydrophobic top coat usually ranges from 1 to 30 nm,preferably 1 to 15 nm.

The remaining steps of this second embodiment of the method of theinvention are identical to those described in relation with FIGS. 1A to1C.

The following examples illustrate the present invention. In theexamples, unless otherwise stated, all parts and percentages are byweight.

1. Two-Part Mold

In all the examples the mold used was made of polycarbonate (GeneralElectric Company).

2. Scratch-resistant coating compositions (hard coating composition) Thefollowing thermal and/or UV curable hard coating compositions wereprepared by mixing the components as indicated hereinunder.

Component Parts by weight Hard coating composition n° 1: thermallycurable Glymo 21.42 0.1N HCI 4.89 Colloidal Silica 1034A 30.50 (35% byweight of solid) Methanol 29.90 Diacetone alcohol 3.24 Aluminumacetylacetonate 0.45 Coupling agent 9.00 Surfactant (1/10 dilution) 0.60Hard coating composition n° 2: thermally curable Glymo 18.6 0.1N HCI6.62 Dimethyldiethoxysilane (DMDES) 9.73 Colloidal Silica/MeOH⁽¹⁾ 60.1Aluminum acetylacetonate 1.2 Methyl Ethyl Ketone (MEK) 3.65 Couplingagent 5.00 Surfactant FC 430⁽²⁾ 0.05 Hard coating composition n° 3:thermally curable Glymo 18.6 0.1N HCI 6.62 Dimethyldiethoxysilane 9.73Colloidal Silica/MeOH⁽¹⁾ 60.1 Aluminum acetylacetonate 1.2 Methyl EthylKetone (MEK) 3.65 Surfactant FC430⁽²⁾ 0.05 Hard coating composition n°4: (UV curable) Glymo 23.75 n-propanol 14.25 Colloidal Silica MeOH⁽¹⁾47.51 Tyzor DC (1% dilution)⁽³⁾ 14.25 UVI-6974⁽⁴⁾ 0.2735 Coupling agent:precondensed solution of: Glymo 10.0 Acryloxypropyltrimethoxysilane 10.00.1N HCI 0.5 Aluminum acetylacetonate 0.2 Diacetone alcohol 1.0 ⁽¹⁾SunColloid MA-ST from NISSAN Company (30% by weight of solid SiO₂)⁽²⁾FC430: surfactant commercialized by 3M Company ⁽³⁾Tyzor:

⁽⁴⁾UVI-6974: Mixture of:

and

3. Impact-Resistant Primer Coating Compositions (Primer CoatingCompositions)

Several primer coating compositions were made by mixing the variouscomponents as indicated below:

Component Parts by weight Impact Primer Coating Composition n° 1a (UVcurable Acrylic) Tetraethylene glycol diacrylate (SR-268) 12.42Aliphatic urethane triacrylate (EB-265) 16.87 n-propanol 20.27 DowanolPM⁽⁵⁾ 20.27 Dowanol PnP⁽⁶⁾ 20.27 Coupling agent 9.00 ITX⁽⁷⁾ 0.063Irgacure 500⁽⁸⁾ 0.60 Surfactant FC-430 (50% dilution) 0.21 Impact PrimerCoating Composition n° 1b (UV curable Acrylic) Polyethylene (400) glycoldiacrylate 12.42 (SR-344) Aliphatic urethane triacrylate (EB-265) 16.87n-propanol 20.27 Dowanol PM 20.27 Dowanol PnP 20.27 Coupling agent 9.00ITX 0.063 Irgacure 500 0.60 Surfactant FC-430 (50% dilution) 0.21 ImpactPrimer Coating Composition n° 2 (thermal curable polyurethane latexW-234) Polyurethane Latex W-234⁽⁹⁾ 35.0 Deionized Water 50.0 2-ButoxyEthanol 15.0 Coupling agent 5.0 or Polyurethane Latex W 234 40.0Deionized Water 40.0 Dowanol PnP 20.0 Coupling agent 5.0 SurfactantL77⁽¹⁰⁾ 0.5 Impact Primer Coating Composition n° 3 (Thermal curable,Acrylic latex A-639) Acrylic latex A-639⁽¹¹⁾ 40.0 Deionized water 40.02-Butoxy Ethanol 20.0 Impact Primer Coating Composition n° 4 (UV curableHybrid) UVR6110⁽¹²⁾ 13.00 HDODA⁽¹³⁾ 10.89 Pentaerithritol pentaacrylate30.36 GE 21⁽¹⁴⁾ 30.29 Diethylene glycol diacrylate 7.01 Isobornylacrylate 2.29 Surfactant 0.09 Mixed triarylsulfonium 0.30hexafluoroantimonate salts Impact Primer Coating Composition n° 5 (UVcurable Hybrid) UVR6110 13.00 HDODA 10.89 Polyethylene glycol (400)diacrylate 30.36 GE 21 30.29 Diethylene glycol diacrylate 7.01 Isobornylacrylate 2.29 Surfactant 0.09 Mixed triarylsulfonium 0.30hexafluoroantimonate salts ⁽⁵⁾Dowanol PM: 1-methoxy-2-propanol and2-methoxy-1-propanol solvent commercialized by DOW CHEMICAL. ⁽⁶⁾DowanolPnP: solvent commercialized by DOW CHEMICAL which is a mixture of:1-propoxy-2-propanol, 2-propoxy-1-propanol, Propyleneglycol,Diethyleneglycol, Dipropylglycolmonopropylether ⁽⁷⁾ITX:Isopropylthioxanthone ⁽⁸⁾Irgacure 500: 1/1 mixture of benzophenone +1-hydroxycyclohexylphenyl ⁽⁹⁾Polyurethane latex commercialized byBaxenden ⁽¹⁰⁾L77 surfactant commercialized by OSI Specialities⁽¹¹⁾Acrylic Latex-A-639 commercialized by Zeneca ⁽¹²⁾UVR61103,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarbonate + monoepoxide of3-cyclohexenylmethyl-3-cyclocarboxylate ⁽¹³⁾HDODA 1,6-hexanedioldiacrylate ⁽¹⁴⁾GE21 1,4-butanediol diglycidylether4. Optical Substrate Compositions

Component Parts by weight Optical substrate composition n° 1(UV/Thermally curable) The following mixture was prepared at 40° C. inthe dark. Tetraethoxy bisphenol A dimethacrylate 980 Methyl butene-1 ol20 Irgacure 1850⁽¹⁵⁾ 1.75 Optical substrate composition n° 2(UV/Thermally curable) Polypropyleneglycol (400) 51 dimethacrylateUrethane methacrylate (Plex ® 66610) 34 Isobornyle methacrylate 15Irgacure 1850 0.1 Optical substrate composition n° 3 (UV/Thermallycurable) Thiomethacrylate⁽¹⁶⁾ 70 Dicyclopentadiene dimethacrylate 10FA321M⁽¹⁷⁾ 20 Methylbutene-1-ol 0.3 UV 5411⁽¹⁸⁾ 0.1 Irgacure 819⁽¹⁹⁾ 0.1⁽¹⁵⁾Irgacure 1850: mixture (50/50 by weight) of:

⁽¹⁶⁾Thiomethacrylate: Plex (6856) sold by RÖHM. ⁽¹⁷⁾FA 321M

⁽¹⁸⁾UV 5411: 2-(2-hydroxy-5-t-ocylphenyl)benzotriazole. ⁽¹⁹⁾Irgacure819: photoinitiator of formula:

5. Preparation of the Mold

Unless otherwise stated, the polycarbonate molds used in the exampleswere prepared as follows:

-   a) The injection-molded polycarbonate mold is de-gated and then    edged. The edging process may create scratches on the surface of the    mold, so tape covering of at least the central portion of the mold    surface is used during edging.-   b) After edging, the mold is wipped, cleaned in ultrasonic system,    and then heated in a clean oven for half an hour at 100° C.    6. Deposition of Hydrophobic Top Coat and Anti-Reflecting Coating

Unless otherwise stated, hydrophobic top coat and anti-reflectingcoating were deposited on the optical surface of the front part of themold as follows:

The hydrophobic top coat and anti-reflecting treatments are accomplishedin a standard box coater using well known vacuum evaporation practices.

-   a—The mold is loaded into the standard box coater such as a Balzers    BAK760 and the chamber is pumped to a high vacuum level.-   b—Hydrophobic top coat, a fluorosilazane (Shin Etsu KP801M), is    deposited onto the optical surface of the first part of the mold    using a thermal evaporation technique, to a thickness in the range    of 2-15 nm.-   c—The dielectric multilayer anti-reflecting (AR) coating, consisting    of a stack of high- and low-index materials is then deposited, in    reverse of the normal order. Details of this deposition are as such:    -   The first layer is a layer of of SiO₂ having a physical        thickness of 80-110 nm (optical thickness about 100-160 nm).    -   The second layer is a layer of ZrO₂ having an optical thickness        of about 160 nm, the third layer is a SiO₂ layer having an        optical thickness of about 30 nm and the fourth layer is a ZrO₂        layer having an optical thickness of about 55 nm (optical        thickness are given at a warelength of 550 nm).-   d—At the completion of the deposition of the four-layer    anti-reflecting stack, a thin layer of SiO₂, having a physical    thickness of 1-50 nm, is deposited. This layer is to promote    adhesion between the oxide antireflecting stack and the subsequent    hard-coating which will be deposited on the coated mold at a later    time.

EXAMPLE 1

The front part of a polycarbonate two-part mold already coated with ahydrophobic top coat and an AR coating was coated with Hard CoatingComposition n^(o) 1. Hard coating application speed was set at 400 rpmfor 8 seconds and spin off speed at 800 rpm for 10 seconds. Hard CoatingComposition is cured by IR for 30 seconds with 725F setting, using LescoIR curing unit. The coated mold was allowed to cool to room temperatureand Impact Primer Coating Composition n^(o) 1a is applied at the samespeed and timing as mentioned above. Impact Primer Coating compositionis cured by UV light, using Fusion system H bulb with belt speed of (5feet per minute) 1.526 m/minute.

Final coating cure was achieved using Lesco IR curing unit set at 725Ffor 30 seconds.

The coated plastic mold was assembled, filled with optical substratecomposition n^(o) 1 and polymerized within 20 minutes. Upon disassemblyof the plastic mold, all of the coatings were transferred to thefinished lens.

EXAMPLE 2

The first part of a polycarbonate two-part mold already coated with ahydrophobic top coat and an AR coating was coated with Hard CoatingComposition n^(o) 1. Hard coating application speed was set at 400 rpmfor 8 seconds and spin off speed at 800 rpm for 10 seconds. Hard CoatingComposition cured by IR for 30 seconds with 725F setting, using Lesco IRcuring unit. The coated mold was allowed to cool to room temperature andImpact Primer Coating Composition n^(o) 1b was applied at the same speedand timing as mentioned above. Impact Primer Coating Composition wascured by UV light, using Fusion system H bulb with belt speed of (5 feetper minute) 1.524 m/minute.

Final coating cure was achieved using Lesco IR curing set at 725F for 30seconds.

The coated plastic mold was assembled, filled with optical substrateComposition n^(o) 1 and polymerized within 20 minutes. Upon disassemblyof the plastic mold, all of the coatings were transferred to thefinished lens.

EXAMPLE 3

The front part of a polycarbonate two-part mold already coated with ahydrophobic top coat and an AR coating was coated with Hard CoatingComposition n^(o) 2. Hard coating application speed was 500 rpm for 8seconds and spin off at 1200 rpm for 10 seconds. Hard CoatingComposition precured in a thermal heated oven for 10 minutes at 80° C.The coated mold was allowed to cool to room temperature. Impact PrimerCoating Composition n^(o) 2 was applied at the application speed 400 rpmfor 8 seconds and spin off 1000 rpm for 10 seconds. Impact PrimerCoating was precured at the same temperature and timing as the HardCoating.

Final coating curing was done in a thermal heated oven for 1 hour at 90°C.

The coated plastic mold was assembled, filled with optical substratecomposition n^(o) 1 and polymerized within 20 minutes. Upon disassemblyof the molds, all of the coatings transferred to the finished lens.

EXAMPLE 4

The front part of a polycarbonate two-part mold already coated with ahydrophobic top coat and an AR coating was coated with Hard Compositionn^(o) 3, this hard coating did not contain a coupling agent. Hardcoating application speed was 500 rpm. for 8 seconds and spin off. at1200 rpm. for 10 seconds. Hard Coating was precured in a thermal heatedoven for 10 minutes at 80° C. The coated mold was allowed to cool toroom temperature. Impact Primer Coating Composition n^(o) 2 was appliedat the application speed 400 rpm for 8 seconds and spin off 1000 rpm for10 seconds. Impact Primer Coating was precured at the same temperatureand timing as the Hard Coating.

Final coating curing was done in a thermal heated oven for 1 hour at 90°C.

The coated plastic mold was assembled, filled with optical substratecomposition n^(o) 1 and polymerized within 20 minutes. Upon disassemblyof the mold, all of the coatings transferred to the finished lens.

EXAMPLE 5

The front part of a polycarbonate two-part mold already coated with ahydrophobic coat and an AR coating was coated with Hard CoatingComposition n^(o) 2. Hard coating application speed was 500 rpm for 8seconds and spin off at 1200 rpm. for 10 seconds. Hard Coating wasprecured in a thermal heated oven for 10 min at 80° C. Coated mold wascooled down to room temperature. Impact Primer Coating Composition 3 wasapplied at the application speed 600 rpm for 8 seconds and spin off 1500rpm for 10 seconds. Impact Primer Coating was precured at the sametemperature and timing as Hard Coating Composition n^(o) 2.

Final coating curing was achieved in a thermal heated oven for 2 hoursat 90° C.

The coated molds were assembled, filled with optical substratecomposition n^(o) 1 and polymerized within 20 minutes. Upon disassemblyof the plastic mold, all of the coatings transferred to the finishedlens.

EXAMPLE 6

The front part of a polycarbonate two-part mold already coated with ahydrophobic top coat and an AR coating was coated with Hard CoatingComposition n^(o) 4. Hard coating application speed was set at 600 rpmfor 8 seconds and spin off speed at 1200 rpm for 10 seconds. HardCoating was UV cured by Fusion system H bull at (5 feet per minute)1.524 m/minute and followed by 30 seconds IR cure at 725F for 30seconds, using Lesco IR curing unit. Coated mold was allowed to cool toroom temperature and impact Primer Coating Composition n^(o) 4 wasapplied at the same speed and timing as mentioned above. Impact PrimerCoating was cured by UV light, using Fusion system H bulb with beltspeed of (5 feet per minute) 1.524 m/minute.

Final coating curing was achieved using Lesco IR curing unit set at 725Ffor 30 seconds.

The coated plastic mold was assembled, filled with optical compositionn^(o) 1 and polymerized within 20 minutes. Upon disassembly of the mold,all of the coatings transferred to the finished lens.

EXAMPLE 7

The front part of a polycarbonate two-part mold already coated with ahydrophobic top coat and an AR coating was coated with Hard CoatingComposition n^(o) 4. Hard coating application speed was set at 600 rpmfor 8 seconds and spin off speed at 1200 rpm for 10 seconds. HardCoating UV is cured by Fusion system H bulb at (5 feet per minute) 1.524m/minute and followed by 30 seconds IR cure at 725F for 30 seconds,using Lesco IR curing unit. Coated mold was allowed to cool to roomtemperature and Impact Primer Coating n^(o) 5 was applied at the samespeed and timing as mentioned above. Impact Primer Coating was cured byUV light, using Fusion SYSTEM H bulb with belt speed of (5 feet perminute) 1.524 m/minute.

Final coating curing was achieved using Lesco IR curing unit set at 725Ffor 30 seconds.

The coated plastic mold was assembled, filed with optical substrateComposition n^(o) 1 and polymerized within 20 minutes. Upon disassemblyof the mold, all of the coatings transferred to the finished lens.

The performances of the finished lenses of examples 1 to 7 are given inTable below:

Steel Dry Bayer wool Transmission Example No. adhesion test abrasiontest test (%) Impact energy (mJ) 1 Well 4.47 1 98.8 692.40 Tc = 1.68 mm2 Well 4.73 1 98.8 1126.60 Tc = 2.56 mm 3 Well 5.35 0 98.9 711.00 Tc =1.38 mm 4 Well 4.37 0 98.9 844.00 Tc = 1.46 mm 5 Well 4.81 0 97.9 339.80Tc = 1.48 mm 6 Well 4.22 0 98.8 62.40 Tc = 1.37 mm 7 Well 2.66 5 98.6849.00 Tc = 1.34 mm Tc = Thickness at center

EXAMPLE 8

This example illustrates the use of a protective and releasing coatingon the optical surfaces of the mold.

In this example, no hydrophobic top coat is used.

The composition of the releasing and protective coating was as follows:

Component Parts by weight PETA LQ (acrylic ester of 5.00pentaerythritol) Dowanol PnP 5.00 Dowanol PM 5.00 n-propanol 5.00 1360(Silicone Hexa-acrylate, Radcure) 0.10 Coat-O-Sil 3503 (reactive flowadditive) 0.06 Photoinitiator 0.20

The polycarbonate molds are cleaned using soap and water and dried withcompressed air. The mold surface are then coated with the abovereleasing and protecting coating composition via spin coating withapplication speed of 600 rpm for 3 seconds and dry speed of 1200 rpm for6 seconds. The coating was cured using Fusion Systems H+bulb at a rateof (5 feet per minute) 1.524 m/minute. A reverse stack of vacuumdeposited AR coats is then applied directly on the above coated molds(without any hydrophobic top coat on the above coated molds) accordingto the general procedure described previously. Once AR coatingdeposition was finished, the molds were coated first with a hard coatingcomposition n^(o) 1 and then with an impact primer coating compositionn^(o) 2, cured, and lenses were cast from optical substrate compositionn^(o) 1.

The stack AR coating/hard coating/primer released well from the surfaceof the coated mold.

EXAMPLE 9

Example 8 is reproduced except that the mold releasing and protectivecoating composition was as follows:

Component Parts by weight PETA LQ (acrylic ester of 4.00pentaerythritol) Dowanol PnP 5.00 Dowanol PM 5.00 n-propanol 5.00 1360(Silicone Hexa-acrylate, Radcure) 2.00 Surface active agent 0.06Photoinitiator 0.20

and a hydrophobic top coat KP801 is used.

The whole stack top coat/AR coating/hard coat/primer released well fromthe coated polycarbonate mold and a lens having very good anti-abrasion,antireflective and impact properties was obtained.

EXAMPLE 10

Example 8 is reproduced except that the mold releasing and protectivecoating composition was as follows:

Component Parts by weight PETA LQ (acrylic ester of 5.00pentaerythritol) Dowanol PnP 5.00 Dowanol PM 5.00 n-propanol 5.00Coat-O-Sil 3509 (reactive flow additive) 0.10 Photoinitiator 0.20

and a hydrophobic top coat KP801 is used.

The whole stack top coat/AR coating/hard coat/primer released well fromthe coated polycarbonate mold and a lens having very good anti-abrasion,antireflective and impact properties was obtained.

EXAMPLE 11

Example 8 is reproduced except that a hydrophobic top coat KP801 is usedand that the molds are coated with the following release coatingcompositions according to the following protocole, before application ofthe subsequent coatings.

Mold coating composition A: Deionized water at 60° C. 0.95 A-1100 (gammaaminopropyl trimethoxy silane) 0.50 Mold coating composition B:Deionized Water at 60° C. 0.95 Dow Q9-6346 (3-trimethoxysilyl propyloctadecyl 0.50 dimethylammonium chloride)

The polycarbonate molds were cleaned using soap and water and dried withcompressed air. The molds surfaces were treated by dip coating in themold coating composition A first for 60 seconds then rinsed off by 60°C. deionized water; then they were coated by dip with mold coatingcomposition B and also rinse off with deionized water at 60° C. Thecoating composition B was cured using Blue M convection oven at 80° C.for 15 min.

The whole stack top coat/AR coating/hard coat/primer released well fromthe coated polycarbonate mold and a lens having very good anti-abrasion,antireflective and impact properties was obtained.

EXAMPLE 12

Example 8 is reproduced except that the molds were coated with afluorocarbon polymer layer as a releasing coating.

Polycarbonate molds were prepared by cleaning ultrasonically in warmedaqueous detergents, then rinsed and dried according to known art. Thepolycarbonate molds were then heated to 100° C. for a period of timefrom 0.1-3 hours, to fully dry the material.

The molds were then loaded in the vacuum chamber with a base vacuumcapability of better than 0.1 Pa. The chamber is pumped to a high vaccumlevel. After an ion bombardment of the mold surface, fluoropolymerTeflon was evaporated onto the mold surfaces using either resistance orelectron beam heating, to a thickness of 2.5 to 150 nm.

Alternatively, the fluoropolymer layer was applied to the mold surfacesprior to vacuum deposition by means of spin- or dip-coating, using adilute solution of soluble fluoropolymers such as Teflon AF, Teflon PTFEFEP, or Teflon PTFE PFA. The thickness of these coatings was 30 to 200nm.

After deposition of the fluoropolymer layer, the oxide anti-reflectingmultilayer stack was deposited (in reverse of the normal order), usingthe process described above.

2 lenses were made, one with a hydrophobic top coat KP801M, and theother one without KP801M.

When used, KP801M hydrophobic material was evaporated on thefluoropolymer layer using resistance heating. Then, the AR coatingSiO₂/ZrO₂/SiO₂/ZrO₂ is deposited.

The layer vacuum deposited final was a thin SiO₂ layer after the stackis completed, to promote adhesion of the AR stack to the siloxane-basedanti-scratch coating. This layer is not optically active, but isincluded only to enhance adhesion of the vacuum-deposited AR stack tothe anti-scratch coating. Thereafter the other layers were deposited andthe lenses cured according to the method described in example 8.

The whole stack AR coating/hard coat/primer or top coat/AR coating/hardcoat/primer released well from the Teflon coated polycarbonate mold anda lens having very good anti-abrasion, anti-reflecting and impactproperties was obtained.

EXAMPLE 13

Example 3 is reproduced, but using optical substrate composition n^(o) 2instead of optical substrate composition n^(o) 1, which is then cured asfollows:

The mold parts are taped in order to produce a cavity and filled using asyringe, with the optical substrate composition n^(o) 2.

A pre-cure was made in 15 s using a iron doped mercury UV bulb suppliedby IST, the intensity was 25-30 mW/cm² (measured 420 nanometer with OM 2radiometer).

Curing was made in IST two side curing oven 2 minutes at 175 mW/cm².

Then curing was achieved in a thermal dynamic air oven, at a temperatureof 80° C. for 8 minutes.

The assembly was edged with the plastic molds in order to generate aclear interface to help molds taking a part.

The complete stack was transferred to the lens.

EXAMPLE 14

Example 13 was reproduced, but using optical substrate composition n^(o)3.

The complete stack was transferred to the lens.

EXAMPLE 15

Example 14 was reproduced but using an allylic formulation using amonomer supplied by PPG under CR607 trade name, catalyzed with 3% byweight of IPP (diisopropylperoxide) and cured using a thermal cyclerising the temperature from 35° C. to 85° C. in 16 hours.

The stack was once against transferred to the lens.

EXAMPLE 16

Example 13 was reproduced but using an optical substrate compositionwhich comprises 52 g of 1,2-bis (2-mercapto ethylthio)-3-mercaptopropane with KSCN catalyst 190 ppm mixed with 48 g ofxylylene diisocyanate.

A gel is obtained at room temperature in 5 minutes, curing is achievedat 120° C. during 2 hours in air oven.

The transfer is made and a very good adhesion is found.

The performances of the lenses of examples 13 to 15 are given in TableII below.

TABLE II Example Bayer Steel wool Dry Transmission No. abrasion testtest adhesion (%) 13 5.6 2 Medium 98.9 14 7.1 9 Good 97.7 15 6.2 0 Good99.1

Bayer abrasion resistance was determined by measuring the percent hazeof a coated and uncoated lens, before and after testing on anoscillating sand abrader as in ASTM F 735-81. The abrader was oscillatedfor 300 cycles with approximately 500 g of aluminum oxide (Al₂O₃) ZF152412 supplied by Specially Ceramic Grains (former Norton Materials)New Bond Street; PO Box 15137 Worcester, Mass. 01615-00137. The haze wasmeasured using a Pacific Scientific Hazemeter model XL-211. The ratio ofthe uncoated lens haze (final-initial) is a measure of the performanceof the coating, with a higher ratio meaning a higher abrasionresistance.

Steel wool scratch resistance was determined as follows:

The lens was mounted coated surface up with double sided tape on the endof a one inch (2.54 cm) diameter pivoting rod. Steel wool (000 grade)was then pressed against the coated surface with a five pounds (2.267kg) weight as back-pressure. The lens was then oscillated for 200 cyclesagainst the steel wool (one inch (2.54 cm) travel), and the hazemeasured. The difference in haze (final-initial) as measured on aPacific Scientific Hazemeter model XL-211 is reported as the woolscratch resistance value.

Coating adhesion was measured by cutting through the coating a series of10 lines, spaced 1 mm apart, with a razor, followed by a second seriesof 10 lines, spaced 1 mm apart, at right angles to the first series,forming a crosshatch pattern. After blowing off the crosshatch patternwith an air stream to remove any dust formed during scribing, clearcellophane tape was then applied over the crosshatch pattern, presseddown firmly, and then rapidly pulled away from coating in a directionperpendicular to the coating surface. Application and removal of freshtape was then repeated two additional times; The lens was then submittedto tinting to determine the percentage adhesion, with tinted areassignifying adhesion failures.

Coating passes adhesion tests when percentage adhesion is more than 95%.

EXAMPLES 17 AND 18

These examples illustrate the use of an organic antireflecting coatingin the process of the invention.

A spin coated, thermal or UV curable antireflective coating (AR) isdeposited on the surface of a thermal plastic mold. The mold assembly iscomprised of a concave and convex mold to form a lens. Subsequently, oneach AR mold surface, a scratch resistant coating was applied andfinally the impact resistant primer coating was deposited. The scratchresistant coating can be formulated to be UV curable or thermal curable.The impact resistant primer coating can be an UV curable coating or alatex thermal curable coating.

The thermal curable AR coating layers can be catalyzed by a metalcomplex via IR curing and contains nanoparticle colloids. The UV curableAR coating layers can be acrylic or epoxy or a mixture of both, curableby free radical or cationic or a combination of both, and containingnanoparticle colloids.

The UV curable scratch resistant coating can be UV curable acryliccoating, cationic, and/or a combination of cationic and free radicalreaction containing nanoparticle colloids. Thermal curable scratchresistant coating can be catalyzed by a metal complex via infra-redcuring. This coating also contains nanoparticle colloids.

The UV curable impact coating consists of the free radical curing of anunsaturated hydrocarbon, cationic curing of an oxirane, and thecombination of cationic with free radical chemistry. Thermal curableimpact coating can be made of acrylic latex or urethane latex and curedby convection heat or an infra-red source.

A coupling agent is used to enhance the chemical bonding between thecoating layers and the substrate system.

Following is the summary of the chemistry and process:

AR Coating Layers:

Low Index Layer

Component Parts Glymo 18.6 0.1 N HCl 6.62 Dimethyldiethoxysilane 9.73Colloidal silica Nissan MA-ST 60.1 Aluminum acetyl acetonate 2.40Isopropyl alcohol 2.55

The coating is then diluted to 3.5% with Ethyl alcohol and surfaceactive agent is added.

High index layer

Component Parts Glymo 4.01 0.1N HCl 2.03 Diacetone alcohol 9.65 NissanHIT32M 32.17 Aluminum acetyl acetonate 0.54 Ethyl alcohol 54.47

A surface active agent is then added.

Nissan HIT 32M is a colloïd composite sol of TiO₂/SnO₂.

Impact primer coating: (UV curable acrylic).

Component Parts Diethylene glycol diacrylate (SR-344) 12.42 Aliphaticurethane triacrylate (EB-265) 16.87 n-Propanol 20.27 Dowanol PM 20.27Dowanol PnP 20.27 Coupler 9.00 ITX 0.063

EXAMPLE 17 Hard Coating n^(o)1, Impact Primer Coating n^(o)1b

The low index layer was deposited onto the mold surface by spin coatingat application speed of 900 rpm and spin off at 2500 rpms for 10seconds. The coating was cured by Casso Lesco IR curing set at 385° C.(725° F.) for 1 minute. The high index layer was deposited onto thecooled mold under the same conditions as the low index layer. Thethermal plastic mold was coated with Hard Coating n^(o)1, again, aftercooling. Hard coating application speed was set at 400 rpm for 8 secondsand spin off speed at 800 rpm for 10 seconds. Hard coating cured by IRfor 30 seconds with (725F) setting, using Lesco IR curing unit. Thecoated mold was allowed to cool to room temperature and Impact primercoating n^(o)6 was applied at the same speed and timing as mentionedabove. Impact primer coating was cured by UV light, using Fusion systemH bulb belt speed of 1,524 m/minute (5 feet per minute).

Final coating cure was achieved using Lesco IR curing unit set at 725 Ffor 30 seconds.

The coated Thermal plastic mold was assembled, filled with UV curableacrylic lens material (Optical substrate composition n^(o)1) andpolymerized within 20 minutes. Upon disassembly of the plastic mold, allof the coatings were transferred to the finished lens.

Following is the performance result:

Bayer abrasion Steel Dry Impact Center % T test wool test adhesion (mJ)thickness (hazegard) 1.93 1.49 Good 559.7 1.36 mm 95.0 Avg. %Transmission of an uncoated lens of the same substrate is 91.4%.

EXAMPLE 18 Thermal Curable, Urethane Latex W-234

Molds were coated with low and high index spin AR layers as in Examplen^(o)17. The thermal plastic mold was coated with Hard coating n^(o)2.Hard coating application speed was 500 rpm for 8 seconds and spin off at1200 rpm for 10 seconds. Hard coating precured in a thermal heated ovenfor 10 minutes at 80° C. The coated mold was allowed to cool to roomtemperature. Impact primer coating n^(o)2 was applied at the applicationspeed 400 rpm for 8 seconds and spin off 1000 rpm for 10 seconds. Impactprimer coating, precured at the same temperature and timing as the Hardcoating.

Final coating curing was done in a thermal heated oven for 2 hours at90° C.

The coated plastic mold was assembled, filled with UV curable acrylic(Optical substrate composition n^(o)1) lens material and polymerizedwithin 20 minutes. Upon disassembly of the molds, all of the coatingstransferred to the finished lens.

Following is the performance result:

Bayer abrasion Steel Center % T test wool test Dry adhesion Impact (mJ)thickness (hazegard) 1.94 1.74 Good 441 average 1.18 mm 94.9Light Transmission Test

Transmission was measured using a BYK GARDNER Haze-guard plus hazemetercatalog n^(o)4725.

Impact Resistance Test

Impact energy was measured using a proprietary system. It can bemeasured by using the protocole of FDA drop ball test with increasingweights for the ball up to the breaking of the lens or the appearance ofa visual crack, generally having the shape of a star, where the ballimpacted. The corresponding energy is then measured.

1. A method for forming a coated optical article comprising the stepsof: (a) providing a two-part mold having opposed optical surfacesdefining therebetween a molding cavity; (b) forming successively, on atleast one of the optical surfaces of the mold an anti-reflectingcoating, a scratch-resistant coating and an impact-resistant primercoating; (c) filling the molding cavity with an optical substrate,liquid, curable composition; (d) curing the liquid curable composition,and (e) disassembling the two-part mold for recovering a coated opticalarticle comprising an optical substrate having deposited and adhered onat least one of its faces, an impact-resistant primer coating, ascratch-resistant coating and an anti-reflecting coating.
 2. The methodof claim 1, wherein the two-part mold is made of a plastic material. 3.The method of claim 2, wherein the two-part mold is made of a plasticmaterial selected from the group consisting of polycarbonates,polyamides, polyimides, polysulfones, copolymers of polyethyleneterephtalate and polycarbonate, crystal polyethylene terephtalate, glassfiber reinforced polyethylene terephtalate and polynorbornenes.
 4. Themethod of claim 2, wherein the plastic material is polycarbonate.
 5. Themethod of claim 2, wherein the plastic material further comprises arelease agent.
 6. The method of claim 5, wherein the release agent isselected from the group consisting of trimethylchlorosilane.chloromethyltrimethylsilane, chloropropyltrimethylsilane, chloromethyldodecyldimethylsilane, chlorine terminated polydimethylsiloxane,(3,3-dimethylbutyl)dimethylchlorosilane, hexamethyldisilazane,octamethyl-cyclotetrasilozane, aminopropyldimethyl terminatedpolydimethylsiloxane, 3-trimethoxysilyl propyl octadecyldimethylammonium chloride, tetradecyldimethyl (3-trimethoxysilyipropyl)ammonium chloride, trimethylethoxysilane and octadecyltrimethoxysilane.7. The method of claim 2, further comprising, prior to step (b), a stepof forming a protective and/or release coating on the optical surface ofthe mold.
 8. The method of claim 7, wherein the protective and/orrelease coating is selected from: UV cured acrylic layer; an aminecontaining polysiloxane layer; a fluorocarbon polymer layer; a vacuumdeposited magnesium fluoride layer.
 9. The method of claim 1, whereinthe anti-reflecting coating comprises a stack of dielectric materiallayers of alternate high and low refractive indices.
 10. The method ofclaim 9, wherein the stack of dielectric material layers is a four layerSiO₂/ZrO₂/SiO₂/ZrO₂ stack.
 11. The method of claim 9, further comprisingthe step of forming an additional SiO₂ layer onto the anti-reflectingcoating for promoting adhesion to the scratch-resistant coating.
 12. Themethod of claim 10, further comprising the step of forming an additionalSiO₂ layer onto the anti-reflecting coating for promoting adhesion tothe scratch-resistant coating.
 13. The method of claim 1, wherein thescratch-resistant coating is formed by curing a composition comprisingas main constituents an epoxyalkoxysilane, a dialkyldialkoxysilane andcolloidal silica or a hydrolyzate thereof.
 14. The method of claim 13,wherein the scratch-resistant coating composition further comprises aneffective amount of a coupling agent which is a pre-condensed solutionof an epoxyalkoxysilane and an unsaturated alkoxysilane.
 15. The methodof claim 14, wherein the epoxyalkoxysilane is selected from the group ofγ-glycidoxypropyltrimethoxy silane,γ-glycidoxypropylpentamethyldisiloxane,γ-glydicoxypropylmethyldi-isopropenoxysilane,(γ-glycidoxypropyl)methyldiethoxysilane,γ-glycid-propyldimethylethoxysilane,γ-glycidoxypropyldiisopropylethoxysilane and(γ-glycidoxypropyl)bis(trimethylsiloxy)methylsilane.
 16. The method ofclaim 14, wherein the unsaturated alkoxysilane is selected for the groupconsisting of tris (2-methoxyethoxy)silane, vinyl tris-isobutoxysilane,vinyl tri-t-butoxysilane, vinyltriphenoxysilane, vinyltrimethoxysilane,vinyltriisopropoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane,vinylmethyldiethoxysilane, vinylmethyldiacetoxy-silane,vinylbis(trimethylsiloxy)silane, vinyldimethoxyethoxysilane,alkyltriethoxysilane, alkyltriethoxysilane andallyltris(trimethylsiloxy)silane,3-acryloxypropyltris(trimethysiloxy)silane,3-acryloxypropyltriethoxysilane, acryloxypropylmethyldimethoxysilane,3-acryloxypropylethylbis(trimethyl-siloxy)silane,3-acryloxypropyldimethylethoxysilane,n-(3-acryloxy-2-hydroxypropyl)-3-aminopropyl-triethoxysilane,3-methacryloxypropylltris(vinyldimethyxyl-siloxy)silane,3-methacryloxypropyltris(trimetholsiloxy)-silane, 3-methacryloxypropyltris(methoxyethoxy)silane, 3-methacrypropyltri-methoxysilane,3-methacryloxypropylpentamethyldi-siloxane,3-methacryloxypropylmethyl-dimethoxysilane,3-methacrylpropylmethyl-diethoxysilane,3-methacryloxypropyldimethylmethoxysilane,3-methacryloxypropyldimethylethoxysilane,3-methacryl-propenyltrimethoxy-silane and 3-methacryloxypropylbis(trimethyl-siloxy)methylsilane.
 17. The method of claim 1, wherein theimpact-resistant primer coating is formed by curing a poly(meth)acrylicbased composition or a polyurethane based composition.
 18. The method ofclaim 17, wherein the compositions are latexes.
 19. The method of claim17, wherein the impact-resistant primer coating composition comprises aneffective amount of a coupling agent which is a pre-condensed solutionof an epoxyalkoxysilane and an unsaturated alkoxy silane.
 20. The methodof claim 19, wherein the epoxyalkoxysilane is selected from the group ofγ-glycidoxypropyltrimethoxysilane,γ-glycidoxypropylpentamethyldisiloxane, γ-glydicoxypropylmethyldiisopropenoxysilane, (γ-glycidoxypropyl)methyldiethoxysilane, γ-glycidoxypropyldimethylethoxysilane, γ-glycidoxypropyldiisopropylethoxy silaneand (γ-glycidoxypropyl)bis(trimethylsiloxy) methylsilane.
 21. The methodof claim 19, wherein the unsaturated alkoxysilane is selected for thegroup consisting of tris (2-methoxyethoxy)silane,vinyltrisisobutoxysilane, vinyltri-t-butoxysilane,vinyltriphenoxysilane, vinyltrimethoxysilane, vinyltriiIsopropoxysilane,vinyltriethoxysilane, vinyltriacetoxysilane, vinylmethyldiethoxysilane,vinylmethyldiacetoxy-silane, vinylbis (trimethylsiloxy)silane,vinyldimethoxyethoxysilane, allyltriethoxysilane, alkyltriethoxysilaneand allyltris(trimethylsiloxy)silane,3-acryloxypropyltris(trimethysiloxy)silane,3-acryloxypropyltriethoxysilane, acrylpropylmethyldimethoxysilane,3-acryloxypropylethylbis(trimethyl siloxy)silane,3-acryloxypropyldimethylethoxysilane,n-(3-acryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane,3-methacryloxyltris(vinyldimethylsiloxy)silane, 3-methacryloxypropyltris(trimethylsiloxy)silane, 3-methacryloxypropyl tris(methoxyethoxy)silane,3-methacryloxypropyltrimethoxysilane, 3-meth-acryloxypropylpentamethyldisiloxane, 3-methacryloxypropyl-methyldimethoxysilane,3-methacryloxypropylmethyldiethoxysilane,3-methacryloxypropyldimethylmethoxysilane,3-methacryloxypropyldimethyl-ethoxysilane,3-methacryloxypropenyltrimethoxysilane and 3-methacryloxypropylbis(trimethylsiloxy)methylsilane.
 22. The method of claim 1, wherein theoptical substrate is a substrate resulting from the polymerization of:diethyleneglycol bis (allylcarbonate) based compositions, (meth)acrylicmonomer based compositions; thio(meth)acrylic monomer basedcompositions; polythiourethane precursor monomer based compositions; orepoxy and/or episulfide monomer based compositions.